The broad objective of this research program is to determine the benefits for maternal-young child brain function and development that can be achieved by preventing/treating malnutrition in a population at high risk from food insecurity. The specific aims of this proposal are to determine the effects of maternal and infant zinc (Zn) supplementation on: maternal-infant cognition, temperament and bonding and on pre-and post-natal brain growth. The proposal includes further development of research resources at Debub University. The research design is a randomized controlled trial (RCT) of 3 different doses (0,12.5 and 25mg Zn/d) of maternal Zn supplementation from early 2nd trimester of pregnancy until 9 months lactation and, nested within this, a second RCT of a low dose of Zn (0 or 3 mg Zn/d) administered to their infants from age 6-9 months. The study will include 900 women and their offspring in five adjacent rural Sidama communities in southern Ethiopia. All mothers will receive a daily multivitamin and energy-protein supplement. Maternal cognition will be assessed longitudinally in the community setting at baseline, 24[unreadable]2 and 34[unreadable]2 wks gestation and 6 and 9 mo lactation by Raven's Colored Progressive Matrices and Kaufman-ABC. Post-partum depression will be assessed by the Edinburgh Post-Partum Depression Scale and maternal-infant interaction by the Nursing Child-Assessment-Feeding and Teaching Scales (NCAST). At age 6 (prior to supplementation) and 9 mo, infant neurocognitive development will be assessed by Novelty Preference;temperament by Laboratory Temperament Assessment Battery plus Bayley Behavior Record;motor function will be assessed by Bayley PDI. Infant head circumference, weight and length will be measured 3 days post- delivery and then monthly. Secondary outcome measures are: incidence of infectious disease morbidity;pre- and post-natal growth;Zn concentrations in maternal plasma and breast milk and the quantity of Zn absorbed. A range of statistical analyses will be used to examine the effects of the 1st RCT (one-way design with 3 groups) and the 2nd RCT (2x3 factorial) with two-sided significance at p=0.05. Improved understanding of the role of Zn is essential to overall understanding of the impact of malnutrition on maternal-infant brain function and development and, thence, to developing optimal public health strategies for the prevention of nutrition-related disorders of brain function.